Process for treating oils



Oct. 20, 1931. c.,P. DUBBS I PROCESS FOR TREATING' OILS Filed Feb. 17,1921 dfbohdzub' @ZMA/MM. Wi

Patented Oct. 20, 1931 e UNITED STATES PATENT OFFICE GABBON P. DUBBS, OFlWlLME'III'JE, ILLINOIS, ASSIGNOR T0 UNIVERSAL OIL .PRODUCTS COMPANY, FCHICAGO, ELIN'OIS, A CORPORATION 0F SOUTH DAKOTA PROCS FOR TBEATING-OILS Application led February 17, 1921. Serial No, 445,670.

This invention relates to improvements in process :tor treating oils andrefers more particularly to a means for bringing an oil process onstream more quickly and more eiiiciently than the usual method-generallyem loyed.

ong the salient objects of the invention are to provide a pro'cess whichmay be more readily brought on stream due to the act that less oil isintroduced to the stream in the initial stages oi the operation of theapparatus; to provide a process in which by producing a localcirculation between the heating zone and vaporizing zones the oil inthat localized portion ci the apparatus may be more readily heated withless fuel coneumption and in a less period of time than is usuallyemployed to bring an apparatus et like capacity on stream; to provide aprocess in which, due t0 the circulation of the oil through the heatingzone and expansion chamber, the carbon deposited from the oil during theheating operation is prevented from Aaccumulating in the heating tubesand kept in suspension with the circulating iiuid whereby dimcultiesfrom hot spots and carhon accumulation in both the heatingand expansionzone are materially lessened; to provide a process which is simple inoperation and necessitates very little additional aipparatus; to providean apparatus for t e carrying out of the described process and, ingeneral, to provide a process and apparatus of the character referredto.

Ylhe single gure isa diagrammatic side elevation partly in section withparts broken away to permit a more complete showing ci the apparatus.

Referring to the drawing-the apparatus can be more simply described byfollowing the course. of the oil in its progress during treatmentthrough the system. The oil is introduced from any convenient source ofsupply (not shown) to the line 1 controlled by a throttle valve 2 and ischarged by a pressure'pump 3 through a line 4 into the top of thedephlegmator 5. Theoil travels down through the dephlegmator` in anopposed direction to the course of the oil vapors which rise therein,the raw oil comved to a crackin ing in intimate contact with the oilvapors serving as a dephlegmating medium, condensing out the higherboiling point `fractions and when combined with them is drawn oil fromthe bottom oi the dephlegmator through a line 6 through which it isdirected to the inlet line 7 of the heating coil 7'. A valve 8 isinterposed in the line 6 and a valve 9 in the line 7. The oil is chargedin this man- 1 ner in startin the process until it stands at the desiredhelght in the expansion chamber at which time the heating coils arecompletely filled, the valve 8 in the line 6 opened and the valve 9 andvalve 10 opened while the valve l1 in the residuuin draw-ofi' pipe 12 isclosed. When the desired quantity of oil has been 'charged into thesystem, the

charging lvalve (not shown) above the dephlegmator is closed. rllhefires are then lighted in the furnace i3 which is preferably heated bymeans or" gas burners 14 and the oil heattemperature. During the heatingof the oi the pump 15 is kept in operation which keeps the oilcirculating th rough the heating tubes into the expansion chamber, outthrough the residuum draw-oil' line and back to the heating tubesthrough the inlet pipe 7, As previously mentioned, the valve 11 isclosed until the oil in the heating tubes 7 and expansion chamber 16 hasbeen raised to a temperature at which a substantial conversion iscommencing to take place. At this juncture in the roces's, oil isgradually admitted to thevinlet ine 7 by opening slightly the chargingvalve (not shown)` above the dephlegmator and as conversion continuesthe pump 15 may be slowly cut out of the system by closing the valves 9and 10. lt will be necessary at this time to draw od the heavy residuumand direct the same to storage through the line 12 by opening the valve11. The oil vapors released in the expansion chamber rise through thevapor line 17 controlled by a valve 18 and after being relieved of theirhigher boiling point fractions by the raw oil in the rectifier ordephlegmator 5, the vapors ass out through the line 19 to a water conenser 20 where, after passing through the coiled pipe 21 they arecollected as distillate in the receiver- 22. A valve 93 is interposed inthe line connecting the condenser and receiver. The receiver is fittedwith liquid level gauge 24, pressure relief pipe 25, controlled by avalve 26 and a liquid draw-off line 27 regulated by a valve 28.

During the initial stagesl of the process it may be advisable to keepthe throttle valve 18 in the vapor line closed in order to decrease theamount of free carbon separation in the heating and expansion zone.

An illustrative run on Mid-continent gas oil would be operatedapproximately under the following conditions :-by introducing' a gas oilof approximately 31 B. gravity and heating the same by a continuouslocal circulation from the residuum draw-off line in tbe expansionchamber back to the heating :zone in the initial stages of the processand raising the oil to approximately 750 F. and at the same timemaintaining a pressure of i rom 50-200 pounds upon the system, thengradually, as the conditions of pressure and temperature become somewhatstable, introducing additional raw oil and simultaneously therewithcutting out the local circulation and directing the heavier ends takenfrom the expansion chamber to storage, I have been able to bring anapparatus much more readily on stream by expanding much less fuel andthereafter proceeding with the process as in operating any othercontinuous cracking apparatus, recovering a distillate having a Baumegravity of approximately 51 and comprising 50 to 60 percent oftheoriginal oil charge.

I claim as my invention:

1. In the art of cracking hydrocarbons, a proces. 'hich comprises theinitial steps of supplying charging oil to a heating coil and expansionchamber, heating the heating coil and pumping the charge of oil fromsaid chamber to the coil and bart` into said chamber. controlling thedischarge of vapors evolved from the oil from said chamber. to graduallyincrease thek pressure in the system to the desired operating pressure.continuing the pumping operation to and'from said expansion chamber. togradually increase the temperature of the charge. then proceeding withthe normal operations of the process. which include prerciting the scapeof liquid from said expansion 'chamber to .said pump,`

pumping a stream of hydrocarbon liquid fromv a source of supply andforcing the hydrocarbon liquid through said heatingr coil and into saidexpansion chamber, passing the vapors through a refiux condenser to anal condenser, continuously permitting refiux condensate to comminglewith the hydrocarbon liquid comingfrom the source of supply, to beforced therewith through said heating coil and into said expansionchamber, regulating the admission of the charging oil from 5 said sourceof supply and removing carbonaceous residue as it accumulates in saidexpansion chamber.

2. In the art of cracking hydrocarbons, the process which comprises theinitial steps of supplying charging stock to a heating coil andexpansion chamber, heating the oil in the coil and pumping the chargefrom said cham ber to the coil and back into said chamber, controllingthe discharge of vapors from said chamber through a reflux condenser andinto a final condenser, to gradually increase the pressure in the systemto the desired operating pressure, and continuing` the pumping operationto and from said separating chamber, to gradually increase thetemperature of the charge, then proceeding with the normal operations,which include preventing escape of liquid from said separating chamberto the pump, conducting a stream of hydrocarbon liquid from a source ofsupply to said reflux condenser, permitting a substantial volume of suchhydrocarbon liquid and reiux condensate, separated from the vapors, toaccumulate` passing vapors from said separating chamber through saidreflux condenser to said nal condenser, continuously forcing a mixtureof reflux condensate and said liquid hydrocarbon from said accumulatedvolume through said heating coil and into said expansion chamber,regulating the supply of liquid hydrocarbon from said source of supply,and removing carbonaceous residue as it accumulates in said expansionchamber.

3. A process of cracking oil, consisting in charging a heating coil andan enlarged reaction chamber with a predetermined quantity ofhydrocarbon oil, in heating the coil while initially repeatedlycirculating the oil through the` coil and the reaction chamber to raisethe oil to a cracking temperature, in controlling the escape ofgenerated vapors to create in the reaction chamber superatmosphericvapor pressure, in proceeding with a normal operation when crackingconditions of temperature and pressure have been attained bydiscontinuingthe cyclic circulation of the oil body through the heatingcoil and reaction chamber, and in continuously supplying fresh chargingoil to the process to e converted continuously subjecting vapors evolvedfrom the oil to reiux condensation, returning the reflux condensate thusformed to said heating coil for conversion with the oil supplied to theprocess while continuously removing unvaporized residue from the reaction chamber without permitting the return thereof to the heatingcoil.

- CARBON P. DUBBS.

